In 1381, Chaucer was busy composing a poem in honor of the arranged marriage between England's Richard II and Anne of Bohemia. This was a very big deal indeed, and Chaucer was looking for just the right saint to honor on May 3, the day Richard II signed the papers of engagement to his Bohemia beauty.

His search ended, Kelly surmises, when Chaucer learned that a Saint Valentine of Genoa had an honorary feast day on May 3. Perfect! So he wrote the poem "The Parliament of Fowls" in the couple's honor.

"The Parliament of Fowls" literally means "the meeting of birds," says Kelly. "Chaucer dreamed up the idea that all birds chose their mates on May 3rd," he says.After Chaucer's death in 1400, Valentine's Day celebrations got pushed back to February.

Why exactly is unclear, however, if you forgot, and someone is upset, perhaps you can use this information to give yourself a few extra months.